Issue #8: expect radius from backend

src/apps/viewer/index.ts

@@ -93,7 +93,7 @@ export class Viewer {
             //       Can we send a precalculated value by our backend?
             //
             // (NOTE: the TMDET extension calculates and sets it during applying preset)
-            radius: 15
+            radius: regionDescriptors[ 'radius' ]
         };
         membrane.planePoint2[2] *= -1;